At the University of Utah we have been testing the feasibility of a new technique for control of prosthetic limbs. The method is the first approach which can be rigorously and rationally expressed in terms of muscle physiology, musculoskeletal anatomy, electromyographic transmission characteristics, and the dynamics of limb motion. With our approach, it is now possible to form a controller, based on biomechanical principles and apply that controller to single or multiple degree of freedom prosthetic limbs. Moreover, since the contoller is rigorously derived, its internal structure is understood; hence, the method holds great promise as a future investigative tool in the area of biomechanics. We have conducted a successful pilot study to test the feasibility of the method. Extensive experimentation on amputees in closed loop control of a one degree of freedom arm prosthesis was successful (elbow flexion). Also, we currently possess the major portion of hardware required to conduct further experimentation. Our present goal is to proceed beyond our one degree of freedom feasibility experiments, to the control of a multiple degree of freedom artificial arm. We will now apply the technique to the simultaneous control of elbow flexion, humeral rotation, wrist rotation, and terminal device closure. At the end of three years, the results of our project will not only be applicable to the control of multiple degree of freedom prosthetic limbs, but to biomechanical investigations and the study of various neuromuscular disorders such as Parkinsonism, palsy, etc.